Improvement in yield has been needed for production of liquid crystal display devices in order to suppress increase in production costs. In production steps of a color filter (CF) substrate as one major member, for example, a method of properly correcting some defects such as lack and contamination, generated in a colored layer or a light-shielding layer has been needed. Application of an ink jet method has been recently investigated as a method of forming a colored layer of the CF substrate. In this case, for example, a liquid material (ink) is added dropwise in each pixel region surrounded by a bank member and then dried and solidified, and thereby a colored layer is formed. However, in the case where the colored layer is formed by the ink jet method, the ink droplets added in different pixel regions are mixed if the bank member has a defective portion, which generates color mixing defective pixels. Therefore, in such a case, a method of correcting the bank member or the color mixing defective pixels has been needed.
As a conventional method of correcting the defects of the CF substrate, a correction method of ejecting a black coloring agent into an abnormal (defective) part such as color void and color mixing of a filter element (pixel) was disclosed (for example, referring to Patent Document 1). A correction method of ejecting a correction liquid with a neutral color into a defective part generated in a colored layer and a light-shielding layer was disclosed (for example, referring to Patent Document 2). Further, a correction method of ejecting a coloring agent of a specified color into an abnormal part such as color void and color irregularity of a filter element was disclosed (for example, referring to Patent Document 3).
However, if these methods are used to correct the bank member or the colored layer, a coloring material for correction is additionally needed in addition to the coloring material used for forming the color layer. In such a respect, there was room for improvement.
With this respect, a method of correcting a pin hole generated in a colored layer by ejecting a coloring material of a color corresponding to a color of the colored layer, without additionally preparing a coloring material for correction, was disclosed (for example, referring to Patent Document 4).
However, this method is thought to be unsuitable for correcting a pin hole generated in a bank formed in a light-shielding region, in terms of light transmittance.
As for the correction method of the defects of the CF substrate, a method of irradiating a defective part with laser light such as excimer laser beam was proposed as a method of removing the defective part (for example, referring to Patent Documents 5 to 8). The defective part is removed by such methods and then a colored layer is formed again at the part from which the defect is removed.
If a color mixing defect is generated in production of a CF substrate using an ink jet device, generally, the color mixing defect spreads into the entire pixel region. Therefore, the entire surface of the pixel region needs to be opened. As a conventional technology for this respect, a method of removing almost the entire color element (pixel) (one pixel) having a defect such as white defect by a laser processing treatment and the like was disclosed (for example, referring to Patent Document 9). However, in these methods, there is a possibility that when the pixel region once causing the color mixing defect is colored again by the ink jet method, the surface of the bank surrounding the pixel regions may exhibit insufficient lyophobicity, and the color mixing defect may be possibly caused again.
Particularly when fluorine plasma treatment is performed as a lyophobic treatment after the pixel opening, the lyophobicity exhibited on the bank surface depends on the bank or a deposit on the bank, and therefore sufficient lyophobicity may not be obtained and the ink may not be kept at a desired position.
[Patent Document 1]
    Japanese Kokai Publication No. Hei-08-292312 (pages 2 and 13, FIG. 9)[Patent Document 2]    Japanese Kokai Publication No. 2003-98336 (pages 2 and 13, FIG. 3(b))[Patent Document 3]    Japanese Kokai Publication No. Hei-07-318724 (pages 2 and 14, FIG. 7)[Patent Document 4]    Japanese Kokai Publication No. Hei-11-271752 (pages 2 and 6, FIG. 3)[Patent Document 5]    Japanese Kokai Publication Hei-05-72528 (pages 2 and 5, FIG. 1)[Patent Document 6]    Japanese Kokai Publication No. 2004-53971 (pages 2 and 11, FIG. 1)[Patent Document 7]    Japanese Kokai Publication No. 2004-13133 (pages 2 and 9, FIG. 2)[Patent Document 8]    Japanese Kokai Publication No. Hei-05-27111 (pages 2 and 4, FIG. 1)[Patent Document 9]    Japanese Kokai Publication No. Hei-03-274504 (pages 1 and 3, FIG. 3b)